The present invention relates to a device for the magnetic treatment of liquids, and in particular for the treatment of water to reduce and prevent the buildup of scale in the pipes and vessels through which the water flows.
In systems and machinery which use large quantities of water, or in which water flows continuously, such as boilers, dishwashers, ice machines, cooling towers, and the like, scale is likely to build up on the surfaces which come into contact with the water. The severity of this problem depends on the mineral content of the water being used, but in most locations in the country and in other parts of the world, some action must be taken to either prevent or remove the buildup of scale on the equipment. Although the equipment can be treated with chemicals in order to remove the scale once it has formed, this procedure is quite expensive and requires continuous maintenance and the periodic shut down of the equipment for descaling. A preferred technique for solving the problem is to treat the water, either before it enters the system or as it is being circulated through the system, by means of a magnetic water conditioner of the general type to which the present invention relates.
Examples of such prior art magnetic treatment devices are disclosed in U.S. Pat. Nos. 3,951,807, 4,153,559, and 4,320,003, and also in copendng Pat. application Ser. No. 167,921 filed July 14, 1980. U.S. Pat. 4,050,426, relates to a device of somewhat similar structure which is utilized for the treatment of fuel in order to improve combustion efficiency and mileage. The disclosures of the aforementioned patents and application are incorporated herein by reference.
Basically, these prior art devices comprise an elongated bar magnet having a multiplicity of longitudinally spaced poles encased in a non-magnetic jacket and concentrically positioned within a casing made of magnetic material, such as galvanized or black iron. Appropriate fittings are connected to the ends of the magnetic casing so that the device can be connected in a water or fuel supply system, and the water or fuel flows through the annular treatment chamber defined between the radially spaced casings so that it is treated by the magnetic fields produced by the magnetic domains within the permanent magnet. The iron casing, since it is made of a ferromagnetic material, functions to short circuit the magnetic lines of force thereby confining the magnetic field to the annular treatment chamber.
Magnetic treatment devices generally of this type are well known and prevent corrosion and the buildup scale by causing the calcium and other minerals present in hard water to form, instead, a loose slurry which can be removed easily from the system by blow down or flushing. The effectiveness with which the water is treated depends on the intensity of the magnetic field within the treatment chamber and the effective length of the chamber itself. In order to effectively treat the water such that the minerals therein will not form as scale on the surfaces of the pipes and vessels, it is necessary that the water be subjected to a sufficient amount of magnetic flux as it passes through the conditioner. Since various installations, such as ice machines, boilers, vehicle cooling systems, etc., operate at widely varying pressures and flow rates, one size of water conditioner will not be sufficient for all applications. For example, the flow rate in a large boiler will be considerably higher than in a small ice making machine so that if the same size water conditioner normally used in the ice making machine were installed on the boiler, the drop in pressure and flow rate would be so great that proper operation of the boiler would not be possible. In order to properly size water conditioners to the particular installation, it has been necessary to develop a number of models over a wide range of flow capacities.
In installations which use all of the water supply without recirculating any of it, the water flows through the conditioner only once so that the water must be subjected to the optimum level of treatment during its cyclic pass through the conditioner. There are many systems, however, in which the water is constantly recirculated, such as in swimming pools, vehicle radiators, air conditioning cooling towers, and solar panels. In these installations, if the water conditioner is connected in series with the water recirculation system, the same water is repeatedly flowing through the water conditioner where it is again subjected to the magnetic field. It has been found, however, that once the water is subjected to the proper amount of magnetic flux, it will retain its scale avoiding properties for period of about 36 hours without retreatment. Accordingly, the constant retreating of the water in a recirculating system of this type is generally unnecessary. In the case of large flow capacity systems, such as in cooling systems of large truck and bus engines, large volumes of water are recirculated and at relatively low pressures. In order to effectively treat the water in a system of this type without resorting to a grossly oversized water condition, a bypass water conditioner of the type disclosed in the aforementioned U.S. Pat. No. 4,320,003, was developed. In such a bypass water conditioner, all of the recirculating water enters the device, but only a portion of it is diverted through the treatment chamber, with the remainder of the water flowing around it in a chamber which is shielded from the magnetic field of the treatment chamber. Although only a small portion of the water is treated during each pass through the unit, the treated portion of the water will become mixed with the untreated portion so that the net effect is full treatment of all of the water in the closed system after recirculation over an extended period of time.
Although a bypass water conditioner of the type disclosed in U.S. Pat. No. 4,320,003, has performed quite satisfactorily, it is sized for only a particular installation having a given flow rate and percentage of bypass. Basically, the magnetic core unit, which is the assemblage of the permanent magnet cores and ferrous shield, is a soldered unit so that it can be disassembled and reconfigured only with great difficulty. Thus, if a unit is constructed for a flow rate of 10 gallons per minute with a 25% treatment and 75% bypass, the user, if he determines that this treatment and insufficient for his particular installation, cannot readily alter the configuration of the water conditioner and must purchase a new unit having the flow capacity and bypass percentage that is desired. Also, if the user wishes to install the water conditioner in a non-recirculating system where 100% treatment of the water is desired, he must substitute a full treatment water conditioner for the bypass water conditioner because of the near impossibility of converting the unit from bypass to full treatment.
In areas where the water has a high iron content, if the user does not use an iron filter in advance of the water conditioner, iron particles may build up on the magnetic cores. After a period of time, the flow passages may become restricted and disassembly and cleaning of the unit may become necessary. With the prior soldered-type units, the user may not be capable of performing this maintenance, and the unit may have to be shipped back to the factory for disassembly, cleaning and reassembly. In larger capacity water conditioners, a single bar magnet may not be sufficient to produce the magnetic flux which is necessary to achieve proper treatment. Accordingly, larger prior art water conditioners comprise a plurality of permanent magnets encased within a sheath, of non-magnetic material and suspended within a single ferrous pipe, which defines the treatment chamber. In this type of unit, the water flows around each of the encased permanent magnets and is subjected to the lines of magnetic flux. It is a known phenomenon that the most effect treatment of the water is achieved by lines of force which intersect the flow of the water perpendicularly. In other words, the lines of magnetic flux which exit from and return to the magnet in a radial direction relative to the axis of the magnet are most effective for treating the water, whereas the lines of force which are more axial relative to the direction of flow, are less effective.
FIG. 8 illustrates, in a diagrammatic fashion, the lines of flux which are present between two magnet cores in a multiple-core water conditioner of the prior art type. It illustrates two bar magnets 10 and 12 having two magnetic domains with axially spaced North, South-South, and North poles. The magnets are encased within a ferrous sleeve 14, which serves to shield the magnets 10 and 12 from the environment and to collect the magnetic lines of force 16 which emanate from the magnet so as to conduct them back to the magnet in the shortest possible length. As can be seen, the magnetic lines of force 16 which are collected by the ferrous sleeve 14 are oriented generally radially relative to the direction of water flow indicated by arrow 18. The lines of flux 20 which extend toward the other magnet 10 or 12, however, are interfered with by the opposing lines of flux so that they tend to travel in an axial direction at approximately the center point between the two magnets 10 and 12. As discussed earlier, lines of flux which are oriented axially to the direction of water flow are much less effective in treating the water, and since the water flow is greater through the center of ferrous sleeve 14 due to friction produced by the inner wall, a considerable portion of the water traveling through the device is not treated in the most efficient manner. This necessitates utilizing a more powerful magnet 10 or 12 or increasing the length of the magnets 10 or 12 in order to produce the desired treatment.